کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1308585 975176 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthetic and mechanistic studies on ruthenium dicarbonyl complexes containing PhP(CH2CH2CH2PCy2)2 (Cyttp) ligand
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Synthetic and mechanistic studies on ruthenium dicarbonyl complexes containing PhP(CH2CH2CH2PCy2)2 (Cyttp) ligand
چکیده انگلیسی

A synthetic and mechanistic study is reported on ligand substitution and other reactions of six-coordinate ruthenium(II) carbonyl complexes containing tridentate PhP(CH2CH2CH2PCy2)2 (Cyttp). Carbonylation of cis-mer-Ru(OSO2CF3)2(CO)(Cyttp) (1) affords [cis-mer-Ru(OSO2CF3)(CO)2(Cyttp)]O3SCF3 (2(O3SCF3)) and, on longer reaction times, [cis-mer-Ru(solvent)(CO)2(Cyttp)](O3SCF3)2 (solvent = acetone, THF, methanol). 2(O3SCF3) reacts with each of NaF, LiCl, LiBr, NaI, and LiHBEt3 to yield [cis-mer-RuX(CO)2(Cyttp)]+ (X = F (3), Cl (4), Br (5), I (6), H (7)), isolated as 3–7(BPh4). These conversions proceed with high stereospecificity to afford only a single isomer of the product that is assigned a structure in which the Ph group of Cyttp points toward the CO trans to X (anti when X = F, Cl, Br, or I; syn when X = H). Treatment of 2(O3SCF3) with NaOMe and CO generates the methoxycarbonyl complex [cis-mer-Ru(CO2Me)(CO)2(Cyttp)]+ (8), whereas addition of excess n-BuLi to 2(O3SCF3) in THF under CO affords mer-Ru(CO)2(Cyttp) (9). The two 13C isotopomers [cis-mer-Ru(OSO2CF3)(CO)(13CO)(Cyttp)]O3SCF3 (2′(O3SCF3): 13CO trans to PC; 2″(O3SCF3): 13CO cis to all P donors) were synthesized by appropriate adaptations of known transformations and used in mechanistic studies of reactions with each of LiHBEt3, NaOMe/CO, and n-BuLi. Whereas LiHBEt3 reacts with 2′(O3SCF3) and 2″(O3SCF3) to replace triflate by hydride without any scrambling of the carbonyl ligands, the corresponding reactions of NaOMe–CO are more complex. The methoxide combines with the CO cis to triflate in 2, and the resultant methoxycarbonyl ligand ends up positioned trans to the incoming CO in 8. A mechanism is proposed for this transformation. Finally, treatment of either 2′(O3SCF3) or 2″(O3SCF3) with an excess of n-BuLi leads to the formation of the same two ruthenium(0) isomers of mer-Ru(CO)(13CO)(Cyttp). These products represent, to our knowledge, the first example of a syn–anti pair of isomers of a five-coordinate metal complex.

The complex [cis-mer-Ru(OSO2CF3)(CO)2(Cyttp)]O3SCF3 undergoes substitution of triflate by various monodentate ligands with high stereospecificity. Its two configurationally stable 13C isotopomers [cis-mer-Ru(OSO2CF3)(CO)(13CO)(Cyttp)]O3SCF3 have been synthesized and used to gain mechanistic insight into reactions with LiHBEt3, NaOMe/CO, and n-BuLi.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Inorganica Chimica Acta - Volume 358, Issue 7, 15 April 2005, Pages 2341–2348
نویسندگان
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